Electric vehicles (EV), hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV) have been heretofore provided with a battery, a drive motor, a driving inverter, and a battery controller (which may be also referred to as EV controller) for detecting the state (including an SOC (State Of Charge) value, a temperature, etc.) of the battery. Some hybrid electric vehicles may have an engine, a power generation motor, a power generation inverter, a power distribution mechanism, etc.
Such an electric vehicle or the like controls the driving states of the motor, the inverter, etc. for the charge/discharge control of the battery based on the state of the battery detected by the battery controller.
Techniques about the charge/discharge control of a battery have been disclosed in Japanese Patent No. 3185674, Japanese Patent No. 4595829 and Japanese Patent No. 4311363. An apparatus disclosed in Japanese Patent No. 3185674 limits the SOC. An apparatus disclosed in Japanese Patent No. 4595829 limits the battery temperature. An apparatus disclosed in Japanese Patent No. 4311363 limits a failure.